Resinous composition and method of making the same



latented Mar. 4, 1 941 p I ,"UNI ED STATEs PATENT OFFICE" YnssmoUs oomosrrlonaun METHOD or MAKINGTHESAME Edmond F. Fledlcr, Adams, Masa, assignor to General Electric Company, a corporation of New York v No Drawing. Application Ann-11 27, 1938,

I Serial No. 204,620

11- Claims. (01.260-44) The present invention relates broadly to resinresinous compositions may be varied. Increasous compositions and to methods. of making the ing, for example,'the ratio of the former to the same. It is more particularly directed to the latter, increases the'fiexibility of the resulting production of casting'resinsof the alkyd-phenolresin. In'accordance with the present invention 5 aldehyde type which are convertible to the inthe alkyd resin components are so proportioned 5 'fusible, insoluble state by heat. The curedresins and reacted for such time as to form a soluble, of this invention are .capable ot being machined alkyd're'sin of the above-described acid number. and drilled easily, maybe clear, translucent or The amount of the alkyd resin incorporated opaque, and in. general meet all the practical with the phenol-aldehydereaction product may 0 requirementsof casting resins. t l 1 v v be varied .over a fairly wide range, depending It has been known heretofore that alkyd-modiupon the particular kind and amount of .phenolic fied phenolic resins can be so prepared as to yield body, aldehyde and catalyst usedyth'e particular resinous compositions capable of being, poured reaction jtlmeand the temperatures employed. into molds, that ,is cast, and cured therein under However, generallyspeaking the alkyd resin heat to the imusible state. Casting resins so ponent will be less than 50 per cent by weight; of 15 made are described, for. example, in Kienle and the dehydrated or cured resinous mass; Schllngman Patent No. 2,025,538, assigned to the The acid number of the alkyd resin to be incorsame ,assignee as. the present invention. In ac,- porated with the phenol-aldehyde reaction prodcordance with the Kienle and Schlingman invenuct should not exceed substantially 210. Othertion a-fiexible alkyd resin having an acid number wise cured casting resins of suitable properties between 140 and-2l0 is used as an acid catalyst in will not be obtained, since a large excess of un promoting reaction between a phenol and an alreacted alkyd resin components (indicated by an 'dehyde such as paraformaldehyde. acidnumber above 210) has a detrimental effect I have discovered that a new series of resins upon the cured product. If the acid value is too can be produced by first reacting a phenolic body, low, for. instance. under approximately 140, more preferably phenol (CeHsOI-I) with an excess of alkyd resin than is desirable is required to neualdehyde, preferably an aqueous solution of an tralize the alkalinity of the alkaline-catalyzed excess of formaldehyde or a compound engenderphenolic resin. Further, at lower acid values it ing formaldehyde, inthenpresence of an alkaline becomes increasingly difficult to obtain, hard, 3 catalyst. Thisreaction is carried out while agitough, practically useful cured casting resins. tating the mass at atemperature not exceeding To obtain light-colored products, materials of substantially 100. C. a high eg ee f purity should be used. The To the above phenol-aldehyde reaction product phenol should be a specially distilled material is added, prior to the complete separation ota substantially free from bodies that would impart resinous condensation'product as an oily mass, a, color to the cured resin.v The catalyst should flexible A-stage alkyd resin 'having an acid nummeet the specifications of the United State ber between approximately 140 and ,210. Alkyd Pharmacopoeia for purity, or bev of an equlvalen resins which are permanently flexible have been grade. The alkyd resin should be almostwater 40 produced and are described and claimed in white. The purest available aldehyde should be 40 Kienle and Rohlfs Patent No. 1,897,260, which is employed. 7

assigned to the same assignee as the present in- The ratio of aldehyde such as formaldehyde to :vention. Briefly, such-resins are prepared by phenol preferably is within the ratio 0111 mol reacting suitable proportions of aliphatic dicarphenol to 1.05 to 4.5 mols formaldehyde. I have boxylic acid, for example succinic acid, adipic obtained best results by uslngl mol phenol to 45 acid and-the like, and dihydric alcohol, such as approximately 3 mols formaldehyde. By varying ethylene glycol, with the usual alkyd resin inthe ratio of phenol to formaldehyde, the rate'of gredients, namely a polyhydric alcohol having cure and strength oi. the final product may be preferably three or more hydroxyl groups in the varied. so molecule, for instance glycerol, and an aromatic The alk line catalyst employed advantageously polycarboxylic acid, such a's phthalic acid orits is one which has no darkening efl'ect upon-the -anhydride.' By varying the ratio of aliphatic dicured resin. Hydroxides of the alkaline earth 'carboxylic acid-dlhydric alcohol ester to polyhymetals (calcium, stronium and barium) and dric alcohol aromatic polycarboxylic acid ester in hydroxides, carbonates, cyanides and borates of 5 the reaction mass, the degree of flexibility of the the alkali metals (lithium, sodium, potassium,

catalysts which maybe used. Potassium cyanide, lithium carbonate,potassium hydroxide and sodium hydroxide were found to be particularly eifective catalysts, their use resulting in the production of cured resins having the best combination of desirable properties (strength, machinability, appearance, toughness, etc.)

The amount of catalyst may be varied, for exam le from 0.5 to- 5 per cent by weight of the phenolic body. The higher the reaction tem perature approaches 100 0., the lower should be the amount of catalyst. Fbr room temperature reaction a higher percentageof catalyst will be: required as compared with reactions carried out.- under applied heat. At reaction temperatures of approximately-75 to 80 C. an'amount of catalyst ranging from 1 to 3.5 per cent by weight of l'so.

tra-limtion is completed by adding a suitablephenol and the aldehyde is allowed to proceed also' the phenol is usually eflective. The percentage used in general will. be somewhat lower, other conditions beingthe same, when hydrc'xidesoi' the alkali metals are used, as compared with the corresponding alkali-metal salts such as carbonates, cyanides and borates. I j

The proportion of alkyd resin tophenolic resin depends upon the particular properties, for example toughness (as distinguished from brittle-j ness and low strength) desiredin the curedjprodu'ct. It also depends uponthe kind and the amount ofcatalyst used, since the alkyd resin serves in most cases as the sole neutralizing agent.

of the base. Ordinarily, the alkyd resin" constitutes from 5 to 45 .per cent, and preferably from .10 to per cent by weight of the dehydrated or cured resinous mass. In generaLthe harder it is desired that the cured resin should be, the less the amount of'alkyd resin wed.

- When a strong base inrelatively large amount is used as catalyst, it is sometimes advantageous to use less acidic alkyd resin than would. be required to'neturalize completely the alkalinity of the phenolic reaction product. 1 In such case neuamountof aweak acid, for example a 'carboxylic acid such as oxalic,.malonic, aconitic, tricarballyllo and the like. Preferably ,I use an hydroxy acid such, for instance, as citric, tartaric or lactic'acid. Inthis way the amount of alkyd resin required for neutralization may be materially reduced.

The initial reaction temperature is important. It should not exceed substantially 100 C. By re?- act'ingthe phenol and formaldehyde at temper atures ranging between 160 and 90"v C. the cured resin is of better color throughout than resins similarly produced by carrying out the initial reaction at a higher temperature. Best results consistent with minimum reaction time are obtained by reacting at temperatures of approximately 70 to 85 C. Temperatures \va'rying from room temperature (20to C.) up to C. also may be used,

but a reaction time of from 8'to 16'hours or more, for example from 1 to 7 days in the case of'room temperature reaction, then may be required before adding the alkyd resin. 7 The extent towhich the reaction between the is important. I have found thatan A-stage alkyd resin is more compatible with the phenol alcoholsand the initial phenol-aldehyde condensation products than with the more highly polymerized phenolic resins. -As is well known, when a phenol and an aldehyde are reacted under alkaline conditionsa phenol alcohol forms first. As the reaction proceeds, a condensation product is formed. The condensation product or resin that forms causes the to first, and if thereaction is allowed to proceed further eventually will result in the separation of an aqueous layer and a thick,

syrupy, oily resinous. layer.

In accordance. with the present invention thephenol andjthe aldehyde are intimatelyvassoci-fl I cient to cause reaction therebetween but insuillcient to cause complete separation, that is to say,

. ated, for example by mixing;- for a period sum. 1

insuillclent to form a distinct layer of a resinous condensation product, before incorporatin: the alkydresin. Thegalkyd resin may be added when the phenolic reaction product is in the form of a,

clearsolution. comprising mainly a mixture of phenolsalcohols, in which case the condensation reaction between the phenol and the aldehyde may be'allowed to proceed further in the presence of the alkyd resin. or the allwd resin may be incorporated in the phenolic resinous mass afterthei initial condensation reaction has started and the condensation product? resultsis throughthemasstoproducetranslucenttoopaque eflects whenhot. -ln'allcases the a-lbd resin'is" a added "before e pre ip t tion of ab ve-d g scribed oily. layer.

In practice the extentof the reaction is con- 7 trolled by the time-of reaction. When reactingat a temperature of approximately 70 to 85 Cebeirt] results have beenobtained when the'phenol and aldehyde were for from one totwo hours. The longer the reaction time at such tempera tures, the more viscous the-resin becomes during subsequent dehydrationy" The casting of too vis- 60113 8. resin results in a'oured product containing bubbles ofentrapped gas. Higher or lower reaction temperatures require shorter-or longer time of reaction to obtain 'a. dehydrated product of approximately the same viscosity.

The temperature at which the alkyd phenol If a temperatureof; 100 C; is attained during dehydration, the cured resin iorms star which are objectionable from the standpoint of appearance and attainment of maximum strength; If

the maximum temperatureof dehydration is 90? C., the cured-product w'ill'be'darker than'it the maximumis, for example, 70".to 85 C. I In prac ticing the praent invention it is important that the dehydration temperature does not exceed substantially 100 .C., and preferably the mass is so dehydrated under reduced pressure that the maxi mum temperature attained is within the range of lzoet aso C. Q 7

During the processor curingthe cast resi'n in molds the temperature should not exceed substantially 100 C. I If the cure temperature is too i objectionable star cracks develop in the cured mass. The higherthe cure temperature, the more.

rapid the cure but the darker the cured product.' Too fasta cure seems to cause brittleness invthe cured resin. I have found that best results are obtained by curing at a temperature which dow not exceed substantially 85 C. and which prefer- "I temperatures, i'orexample from 65 to C. may I ably is ofthe order of to C. Lower curing be'used, but the curing process then. proceeds much more slowly.

When it is desired to color the resin a some dye or pigment isadded, preferably shortly before or immediately after the completion of the dehydration of the resinous. resin is still inthe reaction vessel. 1

In order that those skilled intheait better not i understand howlthe present invention may be ass and while the 4o aldehyde resin is dehydrated likewise is important.

was

. carrled into effect, the following specific examples a reddish. color, indicating. that the liquid .j [mass-was still slightly alkaline. Citric'acidwas f are given to illustrate the invention:

Thealkyl resin was preparedin-theusualway by cooking the ingredients at 190.to 210' 0.. ex-

cept' that the reactionwas stopped in the A -stage upon, reaching an acid value of approximately'.v 180 to 200, and a time of approximatelyseconds when asmall pill of the material wasworked onahct plate maintained at a temperature of about 200" C. The resin was poured into a shallow pan and; broken uplnto pieces for subsequent For convenlence such soluble, A-stage resin willbe referried to in the formulas which follow as 180-200 flexible alkyd resin.

In making the casting resin the following The sodiumhydroxide was 'used in the form or a 10 percent aqueoussolution. A part of the phenol (118 parts) and all 'of the formaldehyde were stirred and reacted together in .thepre'sence of the sodium hydroxide at 75 to 80? C. for 1% to 3 hours, The 'alk'yd resin, previously dissolved in the remaining phenol (72 parts), was added to the reaction vessel. and heating continued for an additional hour at 75 to 80 C. After dehydration under vacuumuntil drythe resulting thick, syrupy mass was poured into molds and cured therein at 80 to 100i C.'for'fr0 m 1 to 3 days;

'EwampleZ, g I .Partsby weight Phenol 118.0 Aqueous formaldehyde (3 7%%) 195.0

Sodium hydroxide 1.6

The phenol, formaldehyde and the sodium hydroxide in the form of a 10 per cent aqueous solutionwere heated together. with stirring for 2 hours at approximately 80 C., after which the alkyd ,reslnin fluid state was added. The mass was dehydrated under vacuum until dry, .re-

quiring' about 1% hours. It waspoured into molds and cured at approximately 80. C. for-42 hours. The cured resin was hard, tough and 10h an initial Charpyimpact test showedanimpact strength above 2 foot pounds. On a second test the sample broke at,1. 35 foot pounds. a

' Example I r Partsbyweight Phenol 118 Aqueous formaldehyde (37V2%) 320 Potassium cyanide 6 180-200 flexible alkyd resin 61 phenol, formaldehyde and the potassium cyanide dissolved'in 20 parts water were stirred and heated together at '75 to C. for 2 hours. Thereafter the alkyd resin] melted to fluid state was added. The resinous solution hours.

havingalmost the-fluidity of vwater when-hot."

'nowj added in the form of a 20 per cent's'olution, a few drops at a time. until the solutionwas neutralized as indicated by a change 11100101 from 'red ma pale yellow. The mass dehydrated under vacuum until dry.

r In this and in all other examples herein given, the usual practice was to apply external heat throughout the period. of dehydration. The temperature would drop-to approximately 88 to 40 C., then rise as the dehydration proceeded.

Generally, after from 2 to .3 hours the-liquid resin wouldreacli 75 to ;80--C., and by controlling thedegree of vacuum an'd the external heat was maintained at that temperature to the end ofthedehydration period.

Resins prepared in'accordance with the above formula, aswell as others herein described, are poured into. molds when apparently dry or, if

desired,fmay-be heated further at 75 to 80C. until the desired viscosity has been obtained.

Resins of this example cured to a hard, tough state in from 1 to 3 days when heated at about 80 C. The Charpy impact strength ranged from I 1 to over 2foot pounds.

Example '4 Y 1 I w Parts by weight Phenol 118.00 Aqueous formaldehyde (til /2%) 100.00

Potassium cyanide -1 2.18 180-200 flexible alkyd resin 20. 00

The phenol, formaldehyde and T the potassium cyanide dissolved in 10 partswater were reacted together with stirring at 75 to 80 C. mr'w,

hours, after'which thealkyd resin in mud state was added. The masswa's dehydrated under reduced pressure until dry,'requiring about 3 The liquid resin was. of low viscosity,

After curingin molds fo'r '1 days at 80 C .it became quite hard, showinga resistanceto impact on the Charpy machine of 0.77 foot pounds.

hours. for example 1% .hours,, at 75 to80 C., after which thealkyd resin in'molten state was added. .The solution becomes a pale yellow color. Some, carbon dioxide is given off, ap-

parently as a result ofreaction between theacid of the alkyd resin and'some oflthe' lithiuincarbonate which has not gone completely, into solution. The mass was heated foranadditional30 minutes, after which it was dehydrated under vacuum. During dehydration, external heat was applied when necessary to reach a maximum temperature of about C. v The mass was dehydrated until dry, requiring about 3 hours. 'After curing in molds atabout 75 to 80C. for 5 days, a hard tough resin having an impact strength on the, Charpy' machine above obtained. f Example 6 Same formula and procedure as uridenEx- 2 foot pounds was ample 5 withthe exception that '2 parts lithium v resin were used. I The mass appeared to. be

.after dehydrating I under reduced pressure for "180400 flexible-alkyd resin; -r 41- same' procedure and reaction time as described 1 hours. A hard, tough machinable resiniwas formed after curing in amcld for '4-days at C.

' Example 7 Parts weight Lithium. hydroxide (dissolved in parts hot watery under Example 4, The mass was dehydrated "under vacuum until dry. After curing in a mold for'5 days at 80 C. a clear, hard; water-resistant, oil-insoluble resin was; obtained. It was extremelyres'istant to' ultra violet light and showed .The phenol, formaldehyde and the sodium borate dissolved in .10,parts water were reacted together with agitation for, 2 hours at 80 C.,'- after which the meltedfalkyd resin was .added. The

;mixed components were reacted together'anoth'er minutes at 80 C.,' thereafter heingdeh'ydrated under vacuum until dry. Clear, tough pieces,

Gii

' free from'blisters. or cracksresulted upon curing in a mold at 85, C."for 40hours,

Examplefl .-1

. Parts by weight Barium hydroxide 12 180-200 flexible, alkyd resin The-phenol, formaldehyde and the barium hydroxide dissolved in 5 parts hot water were heat, ed togetherat C., while stirring, for 1% hours.

. The alkyd resin in fluid state was added and the mass was dehydrated under vacuum until apparently dry and of suitable viscosity'for easein pouring. A hard, cured opaque resin resulted after curing in a mold forli days at 80 C. v

' By themethod of this invention homogeneous, bubblefree casting resins of uniform characteristics from batch to batch are obtained: The ratepfcuring is comparable'with, a'nd in many case'sbetter than thatof casting" resins produced by. other methods and of different composition.

The cured products are mechanically strong and of varying degrees ofttoughness, depending upon such factors as hereinbefore set forth. The

strength of the cured iresin, as .measured by.

breaking a inch diameter by5 incheslong cylinder'on' a Charpy test'm'achine, ranges from about 0.7 foot pounds to above the measuring capacity of the machine, whichis 2 foot pounds.

The lower values are obtained at the lower formaldehyde to phe'nolratios; also, when the resin is cured too long or formulated so'as to cure too fast; Transparent as well astranslucent or opaque "eifects may 'be produced by'varying the formula and the extent of dehydration. The cured resins are water-resistant, oil-insoluble and extremely resistant to ultra-violet'light.

The properties of the cured. resinsmay be varied by using. phenolic bodiesother than pure phenol," for' example cresol or mixtures of phenol 2,989,406 carbonate-and so. are 1so 2qo nexi ielaiiyd.

' hyde. However, I prefer to iisef phenol and fomaldehyde as starting materials. The flexibilgity ,ot the cured resin'also canbevaried by using i; alkyd resins of varyingfratiosf of dihydric alcohol polybasic aromatic acid ester. With conditions i otherwise the same,.the cureicasting resin will 1 be more flexible the former to the latter;

h r th iai i of th y,

l0. The resins areadapted tcbe cast in any de- "sired"shape. They can be cast, for example, in

.jtin, brass, glass or. oti. molds. They canbe turned easily on a lathe, or drilled, without chip "ping 'or' cracking, and maybeemployed to make a" wide variety of useful articles. Examples of such articles are rods, sheets. tubes, clock cases, I door knobsfltelephone receiving sets; radio cabi- -nets, vasesand umbrellahandles";

l The "dehydrated "resins before curing 'areisufii-z" c ently liquid that they maybe poured without,

difiiculty, Hence they maybe used a p nating agents 'without'solvents. They mayibe employed, for example, to impregnate paper-.im

'sulated layer-wound coils which, after curing, are the equivalent of a molded coil;

Letters Patent of the Unitedstates, is: 1. associating one mol of aphenol with more than one molof formaldehyde in, the presence of an What I -claim as new and desire to secure by alkaline catalyst andat a .temperature not e method which "comprises,.-intimately 30" ceeding substantially;'l00 C." for "a period'suflicient' to react the phenol and formaldehyde but. insufficient toform' ajdistinct layer of a resinous condensation product, inco p rating into the re- .sultingliquid resinous reaction product ajsoluble alkyd resin having an acid number between ap} proximately 140 and '210 at least partly to .neu-

tralize thesaid reaction product andt'o impart plasticity to the cured' re'sinous mass, said alkyd resin being the product of reaction of an aromatic polycarboxylic acid, an alcohol having'at', least. three hydroxyl groups, an aliphatic dicarboxylicacid and a dihydric alcohoLand dehydrating the substantially 100 C.

2. The method which "comprisesr mixingf one mol of phenol with an aqueous solutionpfmore than one mol of'formaldehyde in the presenceof a catalyst. selected from the class consisting of I the hydroxides, carbonates, cyanidesand -borates of the alkali metals at:atemperaturebetween 60? and f for a period sufilcient tofreact-the phenol and formaldehyde butinsufficient to'forma 'dis} tinct layer of a resinous condensation product ingcorporating into the resultingliquidresinous re.- j

action product a soluble'alkydresinj having'an..

acid number between approximately 140' and 210 in an amount .s'ufllcient to iimp'art [plasticity and toughness to the cured resin but insuflicient' to neutralize completely'the alkaline phenolic resinous reaction product, saidyalkyd resin being the product of reaction of an-aromatic polycarboxylic acid, an alcoholhaving at least; threehydroxyl groups, an aliphatic dicarboxylic acid. and a di 'hydric alcohol, addingto the alkyd-modified res inous product an organic .acid'in an-jamount sufii cient to neutralize the same, dehydrating the neu-" tralized resinous mass under reduced fpressurei at' a temperaturenot exceeding substantially. i 0.,

and casting and curing the product; so produced at a temperature not'less than 65""C.and notex-j (Seeding Substantially 100 C.

.5 dibas ic aliphatic acid ester to polyhydric alcoholj 45 liquid alkydmodifled'res'inous product under re- 'duced pressure at a temperature not exceeding 3. The method which comprises reacting phenol with an aqueous solution of formaldehyde in the ratio of 1 mol phenol to from 1.05 to 4.5 mols formaldehyde, said reaction'being carried out in the presence of a relatively small proportion of potassium cyanide as a catalyst at a temperature between and C. for a period sumcient to react the phenol and formaldehyde but insufficient to form a distinct layer .of a resinous condensation product, incorporating into th resulting liquid resinous reaction product a soluble alkyd resin having an acid number between approximately 140 and 210. in an amount corresponding to from 5 to 45 per cent by weight of the completely dehydrated resinous mass, said alkyd resin being the product of reaction of an aromatic polycarboxylic acid, an alcohol ihaving at least three hydroxyl groups, an aliphatic dicarboxylic acid and a dihydric alcohol, and dehydrating the liquid alkyd-modified resinous product under reduced pressure at a temperature not exceeding .the said product a soluble alkyd resin having an acid number between approximately 140 and 210 in an amount corresponding to from 10 to 30 per cent by weight of .the cured resin, said alkyd resin being the product of reaction of an aromatic polycarboxylic acid, an alcohol having at least. three hydroxyl groups, an aliphatic dicarboxylic acid and a dihydric alcohol, dehydrating the alkyd-modiiied liquid phenolic resinous product at a temperature not exceeding substantially 85 C., and casting and curing the product so produced at a temperature not less than 65 C. and not exceeding substantially 85 C.

5. A casting resin adapted to be cured at a temperature not less than 65 C. and not exceeding substantially C., said resin being. the product of the method of claim 1.

6. A hard, tough cast resin which is the product of the method of claim 2.

7. The method of preparing a casting resin suits, adding to the said clear solution a soluble acidic alkyd resin in an amount sufficient to neutralize the alkalinity due to the catalyst employed and to impart toughness and plasticity to the cured resin, the said alkyd resin having an acid number between approximately and 210 and being the product of reaction of glycerine, phthalic anhydride, ethylene-glycol and adipic acid, causing the phenol-formaldehyde reaction to proceed further in the presence of the said acidic alkyd resin, and dehydrating the resinous reaction product thereby obtained at a tempera- Lure not exceeding substantially 100 C.

8. The method which comprises effecting reaction between phenol and an aqueous solution of formaldehyde in the ratio of one mol phenol to more than one mol formaldehyde in the presence of an alkaline catalyst and at a temperature not exceeding substantially 100 C. for a period sufficient to form a liquid initial condensation product comprising a phenol alcohol, incorporating into the said condensation product a soluble alkyd resin having an,acid number between approximately 140 and 210, said alkyd resin being the product of reaction of an aromatic polycarboxylic acid, an alcohol having at least three hydroxyl groups, an aliphatic dicarboxylic acid and a dihydric alcohol and constituting not exceeding substantially 50 per cent by weight of the completely dehydrated resinous mass, and dehydrating the resulting product to obtain a casting resin adapted to be cured within the temperature range 

